Mineral wool blanket having imprinted surface and method of making the same



y 1962 J. s. GILHART 3,045,316

MINERAL WOOL BLANKET HAVING IMPRINTED SURFACE AND METHOD OF MAKING THE SAME 2 Sheets-Sheet 1 p 0% mm hm Filed July 19.. 1957 INVENTOR.

Jack 8. Gil harr ATTORNEY Jilly 24, 1962 J. s. GILHART 3,045,316

MINERAL WOOL BLANKET HAVING IMPRINTED SURFACE AND METHOD OF MAKING THE SAME Filed July 19. 1957 2 Sheets-Sheet 2 INVENTOR. Jack 5, Gilharr ATTORNEY Ohio, assignor to The Babcock & Wilcox Company,

New York, N.Y., a corporation of New Jersey Filed July 19, 1957, Ser. No. 673,026

7 Claims. (Cl. 2872.3)

This invention relates to the formation of pads or blankets of mineral wool and, more particularly, to a novel method of and apparatus for imparting predetermined surface configurations to such pads or blankets, the configurations facilitating application of the pads or blankets to surfaces to be protected thereby.

In my copending application Serial No. 556,597 filed December 30, 1955, now abandoned, I have described and claimed a method of forming a pad of mineral wool fibers involving the steps of initially lubricating the fibers as they are attenuated, compacting the lubricated fibers into a blanket or pad and, while the fibers are thus compacted, removing the lubricant so that the fibers remain compacted by virtue of the interlocking of the fibers with each other due to their brashness. The lubricant employed is preferably an oil water emulsion containing a small amount of a waterproofing agent, such as a fatty acid amine salt, in the preferred ratio of five parts of oil to one part of the agent. The concentration of the agent in the emulsion can be as low as 0.001%.

In accordance with the present invention, it has been found that if, during the step of compacting the fibers to form a blanket or pad, the surface of the blanket or pad is simultaneously formed with a series of substantially parallel and rectilinear indentations therein, several important advantages with respect to the finished product are obtained. These advantages are even more pronounced when both surfaces of the blanket or pad are imprinted with a rectilinear grid of indentations to provide a waflle effect.

For example, any surface blemishes on the mineral wool resulting from the wool fibers becoming overlapped, or curled from being dragged over a support surface, as well as particles of shot, become obscure under the imprinted pattern. Secondly, the Wafiied surface provides natural crease marks about which the blanket can be folded when it is wrapped around some objects to be insulated, thus resulting in the blanket wrapping around the object and conforming more uniformly to the insulated object. Furthermore, the finished blanket looses some of its stiffness without becoming weakened. Ancillary advantages are that the. blanket appears more attractive and uniform and the pattern of indentations gives the blanket a distinctive appearance.

In the formation of a blanket in accordance with the invention, the mineral wool fibers lubricated as described in my said prior application are discharged on to a moving conveyor and initially slightly compacted while the conveyor is moving the fibers toward an oven in which the fibers are heated to remove the lubricant from the compacted fibers. At the entrance to this oven, the conveyor feeds the fibers between a pair of cooperating pressure rolls whose surfaces are formed with reliefs in the desired configuration to be imprinted on the blanket. As these rollspress the fibers into compacted condition, the surfaces of the compacted pad or blanket have imprinted thereon the desired pattern. The thus imprinted and compacted blanket then passes therebetween a pair of elongated endless conveyors which pass the blanket through the drying oven to heat and drive off the lubricant so that, as the blanket leaves the oven, the

I United States Patent to the oven are preferably made of some corrosion resistant metal such as, for example, a stainless steel. A convenient way for forming reliefs on the surfaces of these rolls to imprint the pattern on the pad is to wrap the rolls with a stainless steel relatively large mesh screen which may be welded to each of the rolls. Such a screen will imprint on the two surfaces of the pad or blanket a grid of indentations giving the surfaces the abovementioned wafiled effect. While it is preferred to form a grid pattern on both surf-aces of the blanket, it is desired to point out that such a pattern may be provided on only one surface or, alternatively, a series of parallel rectilinear indentations may be formed across or along one or both surfaces of the blanket or linearly thereof.

For an understanding of the invention principles, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing.

In the drawing:

FIG. 1 is a side elevation view illustrating a complete apparatus for forming a blanket in accordance with the present invention;

FIG. 2 is a side elevation view, to a larger scale, of part of the apparatus shown in FIG. 1, with the drying oven being shown in vertical section;

FIG. 3 is a perspective view illustrating the pressure roll means at the entrance to the drying oven; and

FIG. 4 is a partial elevation view of a preferred form of pressure roll means.

Referring to FIG. 1 of the drawings, mineral material, such as kaolin, is fed from a supply hopper 10 through a conduit 11 into an electric resistance furnace 12 where the mineral material is melted. The molten material is discharged through a bottom tap nozzle 13. The stream of molten material discharged from nozzle 13 is subjected to a high velocity jet or stream of air or steam discharge from nozzle 14. The high velocity jet or stream attenuates the molten material to form fibers which are blown into a wool duct 15 leading to a wool box 16. Fine material, such as shot, is discharged from duct 15 through an extension 17, but the fibers move through a conduit section 18 into the wool box.

The fibers discharged into wool box 16 from the outlet of conduit section 18 are coated with a lubricant of the character described in my said prior application which is sprayed onto the fibers by spray means 20 (FIG. 2) at the entrance to box 16 and adjacent the discharge end of conduit section 18.

In wool box 16, the fibers 21 fallv onto the upper run of an endless conveyor 22 passing through the wool box, a partition 23 extending over and in spaced relation to conveyor 22. Just beneath the upper run of conveyor .22 is a suction box 23 connected by a conduit 24 to a vacuum creating arrangement 25 on top of the Wool box. The suction box 23 tends to maintain the space in the wool box at a negative pressure, thus facilitating movement of the fibers into the wool box and tending to compact the fibers on to the upper run of conveyor 22.

The pile of fibers on the upper run of conveyor 22 is compacted intoa substantially uniform depth layer of fibers by a pinch roll 26 mounted at the exit end of lthe wool box and in pressure engagement with the fibers on conveyor 22. The thus compacted fibers leaving the conveyor 22, which latter is an open mesh conveyor, are delivered to a second conveyor 27 disposed between the discharge end of conveyor 22 and the entrance to a heating oven 30. At the entrance 3-1 of oven the compacted fibers are engaged by imprinting means such as the pattern rolls which further compact the fibers into substantially the ultimate thicknessof the blanket and also imprint the pattern thereon as described more fully hereinafter. The further compacted'fibers emerging from rolls 35 are delivered between the lower run of an endless conveyor 32 and the upper run of an endless conveyor 33, conveyors 32 and 33 extending substantially the full length of the heat treating oven 30. These conveyors maintain the fibers in their compacted condition while the lubricant applied by sprays 20 is driven off the fibers by the heat in oven 30.

Due to the brashness of the fibers, the fibers maintain their compacted position after the lubricant is driven off. The lubricant has the property of facilitating movement of the fibers over each other, thus substantially eliminating breakage of the fibers due to such compacting. The completed blanket emerging from the exit end of oven 30 is transported by an endless conveyor 34 adjacent which are edge trimming or spreading wires 36. The blanket may be cut to length by a cut off knife 37 and wrapped up on a spindle roll, or the like 38. Rolls 41 beneath roll 38 support the blanket during the wrapping up operation.

Referring to FIGS. 3 and 4, the pattern rolls 35 are preferably stainless steel rolls each having welded or otherwise secured thereto a layer of stainless steel wire mesh or screen 45 which imparts the desired grid pattern to the surfaces of the blanket. While the illustrated pattern is a grid pattern, it is within the purview of the invention to impress only one surface of the blanket with the desired pattern or to impress thereon a different type of pattern, such as one comprising parallel spaced indentations extending transversely of the blanket on one or bothsurfaces, or parallel spaced indentations extending longitudinally of the blanket on one or both surfaces.

In any event, the configurations or indentations impressed on one or both surfaces of the blanket facilitate the wrapping of the blanket as an insulation around any desired object and also facilitate rolling up of the blanket, as shown in FIG. 2, without damage to the blanket.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

l. The method of forming a flexible pad from a conglomerate mass of brash blown mineral wool fibers, comprising the steps of lubricating the individual fibers; collecting and mechanically compacting the lubricated fibers in a conglomerate mass of random orientated fibers to form a pad; impressing on at least one outer surface of the pad of lubricated fibers a series of spaced substantially parallel and rectilinear indentations; and, while the fibers are compacted, drying and heating the same to remove the lubricant.

2. The method of forming a flexible pad from a conglomerate mass of brash blown mineral wool fibers, comprising the steps of lubricating the individual fibers; collecting and mechanically compacting the lubricated fibers in a conglomerate mass of random orientated fibers to form a pad; impressing on the outer surfaces of the pad of lubricated fibers a series of spaced, substantially parallel and rectilinear indentations; and, while the fibers are compacted, drying and heating the same to remove the lubricant.

3. The method of forming a flexible pad from a conglomerate mass of brash blown mineral wool fibers, comprising the steps of lubricating the individual fibers; collecting and mechanically compacting the lubricated fibers in a conglomerate mass of random orientated fibers to form a pad; impressing on at least one outer surface of the pad of lubricated fibers a series of longitudinally spaced substantially parallel and rectilinear indentations extending substantially transversely of the pad; and while the fibers are compacted, drying and heating the same to remove the lubricant.

4. The method of forming a flexible pad from a conglomerate mass of brash blown mineral wool fibers, comprising the steps of lubricating the individual fibers; collecting and mechanically compacting the lubricated fibers in a conglomerate mass of random orientated fibers to form a pad; impressing on at least one outer surface of the pad of lubricated fibers a substantially rectangular grid composed of two series of spaced substantially parallel and rectilinear indentations; and, while the fibers are compacted, drying and heating the same to remove the lubricant.

5. The method of forming a flexible pad from a conglomerate mass of brash blown mineral Wool fibers, comprising the steps of lubricating the individual fibers; collecting and progressively mechanically compacting the lubricated fibers in a conglomerate mass of random orientated fibers to form a pad; progressively impressing on at least one outer surface of the pad of lubricated fibers a series of spaced substantially parallel and rectilinear indentations; and while the fibers are compacted and after the pad is impressed, progressively drying and heating the same to remove the lubricant.

6. The method of forming a flexible pad from a conglomerate mass of brash blown mineral wool fibers, comprising the steps of lubricating the individual fibers; collecting and progressively mechanically compacting the lubricated fibers in a conglomerate mass of random orientated fibers to form a pad; progressively impressing on at least one outer surface of the pad of lubricated fibers a substantially rectangular grid composed of two series of spaced, substantially parallel and rectilinear indentations; and While the fibers are compacted and after the pad is impressed, progressively drying and heating the same to remove the lubricant.

7. The method of forming a flexible pad from a conglomerate mass of brash blown mineral wool fibers, comprising the steps of lubricating the individual fibers; collecting and progressively mechanically compacting the lubricated fibers in a conglomerate mass of random orientated fibers to form a pad; progressively impressing on the outer surfaces of the pad of lubricated fibers a substantially rectangular grid composed of two series of spaced, substantially parallel and rectilinear indentations; and while the fibers are compacted and after the pad is impressed, progressively drying and heating the same to remove the lubricant.

References Cited in the file of this patent UNITED STATES PATENTS 1,384,808 Shiner July 19, 1921 1,864,317 Powell June 21, 1932 2,335,102 Bergin et al Nov. 23, 1943 2,416,390 Hitt Feb. 25, 1947 2,441,390 Boeddinghaus May 11, 1948 2,501,979 Wood et al Mar. 28, 1950 2,641,027 Taylor June 9, 1953 2,728,699 Labino Dec. 27, 1955 2,746,096 Baxter et al May 22, 1956 2,774,129 Secrist Dec. 18, 1956 2,803,188 Duvall Aug, 20, 1957 2,931,421 Schuller Apr. 5, 1960 FOREIGN PATENTS 630,666 Great Britain Oct. 19, 1949 

